JP7109283B2 - travel control device - Google Patents

Description

The present invention relates to a traveling control device for a traveling vehicle having a pair of left and right traveling control units capable of driving a pair of left and right drive wheels, respectively.

Conventionally, as a technique for improving the steering performance of a vehicle, a technique for driving a pair of left and right drive wheels independently of each other has been studied. As this type of technology, for example, there is a technique described in Patent Document 1, the source of which is given below.

Patent Literature 1 describes a vehicle steering system. In this vehicle steering system, left and right operation handles are attached to the vehicle body so as to be rotatable independently of each other. When the left and right operation handles are rotated in the same direction, the turning device is controlled according to a first rotation angle, and when the left and right operation handles are rotated in opposite directions, a second rotation angle is obtained. Accordingly, it controls the forward, reverse and travel speed of the travel device.

Japanese Patent Application Laid-Open No. 2010-6126

The technique described in Patent Document 1 compares the left and right steering angles with predetermined first and second reference steering angles, and determines whether the input to the operating handle is gentle steering or sharp steering. It is determined whether the steering is correct. Specifically, when the steering angle input to the operating handle is smaller than the first reference steering angle, the rotation speed of the electric motor on the inner side of the turn is controlled to be reduced by a constant value. Make a relatively gentle turn in the direction. On the other hand, when the steering angle input to the operating handle is within the range from the first reference steering angle to the second reference steering angle, the electric motor on the inner side of the turn is stopped and the vehicle can easily turn toward the inner side of the turn. Let Furthermore, when the steering angle input to the operating handle is larger than the second reference steering angle, the electric motor on the inner side of the turn is controlled to be reversed, and the vehicle is rapidly turned toward the inner side of the turn.

For example, when a pair of left and right drive wheels are rotated in opposite directions to turn the vehicle on the spot, the reaction force from each mechanism such as the transmission, the reduction gear, and the engine is not received, and the movement of the vehicle body is not affected. Since it is operated, there is a possibility that the turning operation may be input with high sensitivity. Therefore, there is a possibility that the speed of the vehicle cannot be properly controlled.

Therefore, there is a demand for a travel control device capable of appropriately turning the traveling vehicle and appropriately controlling the speed of the traveling vehicle.

A characteristic configuration of a cruise control device according to the present invention is a cruise control device for a traveling vehicle having a pair of left and right drive control units capable of driving a pair of left and right drive wheels, respectively. an instruction reception unit that receives an operation instruction; a speed instruction value calculation unit that calculates a speed instruction value to be instructed to the travel control unit based on the operation instruction; and a pair of left and right driving wheels based on the operation instruction. an operation instruction determination unit for determining whether an operation instruction to rotate the pair of left and right driving wheels in the same direction or an operation instruction to rotate the pair of left and right driving wheels in directions different from each other; A speed instruction for correcting one of the speed instruction values for the travel control unit calculated by the speed instruction value calculation unit based on the other speed instruction value when the operation instruction is to rotate in the direction and a value correction unit , wherein the speed instruction value correction unit subtracts the smaller one of the one speed instruction value and the other speed instruction value from the larger speed instruction value to obtain the turning component. is extracted, the smaller speed command value is used as it is, and the larger speed command value is corrected based on the turning component .

With such a characteristic configuration, it is possible to reduce the turning speed and improve the straightness. Moreover, even though the turning speed is attenuated, it is possible to avoid a decrease in the maximum speed of the traveling vehicle. Therefore, according to the travel control device, the traveling vehicle can be turned appropriately, and the speed of the traveling vehicle can be appropriately controlled.

Moreover, with such a configuration, it is possible to alleviate turning hypersensitivity by a simple calculation using software. Therefore, since a separate mechanical mechanism is not required to alleviate the hypersensitivity to turning, it can be realized at low cost.

Further, when the operation instruction is an operation instruction to rotate the pair of left and right driving wheels in directions different from each other, the speed instruction value correction unit corrects the speed for the travel control unit calculated by the speed instruction value calculation unit. Preferably, each indicated value is corrected based on the same preset damping value.

With such a configuration, it is possible to attenuate the turning hypersensitivity even when the traveling vehicle is turned on the spot.

1 is a perspective view of a traveling vehicle equipped with a travel control device; FIG. 1 is a system diagram showing an electric system and a power system of a traveling vehicle; FIG. 1 is a block diagram showing the configuration of a travel control device; FIG.

A travel control device according to the present invention is configured to appropriately turn a traveling vehicle and to appropriately control the speed of the traveling vehicle. The traveling control device 1 of this embodiment will be described below. A traveling control device 1 is mounted on a traveling vehicle having a pair of left and right traveling control units 3 capable of driving a pair of left and right driving wheels 2, respectively (see FIG. 3).

FIG. 1 shows a perspective view of a riding electric lawn mower, which is an example of a traveling vehicle in which a traveling control device 1 of the present embodiment is mounted. FIG. 2 also shows an electric system diagram and a power system diagram. As shown in FIGS. 1 and 2, the electric riding lawn mower includes a vehicle body 15 supported by caster wheels 4 as front wheels and driving wheels 2 as rear wheels, a battery 20 arranged at the rear of the vehicle body 15, A driver's seat 11 arranged in front of the battery 20, a fall protection frame 12 erected from the rear of the driver's seat 11, and a lift link mechanism between the caster wheels 4 and the drive wheels 2 in the space below the vehicle body 15. A mower unit 13 suspended from a vehicle body 15 so as to be able to move up and down is provided. The drive wheels 2 are driven by a travel control unit 3 whose operation is controlled by the travel control device 1 , and the mower unit 13 is controlled by a mower control device 5 . Here, the caster wheels 4 are composed of a left caster wheel 4a and a right caster wheel 4b, and the drive wheels 2 are composed of a left drive wheel 2a and a right drive wheel 2b.

A floor plate is provided in front of the driver's seat 11 as a footrest for the driver, and a brake pedal 14 protrudes therefrom. On both sides of the driver's seat 11, a left control lever 6a and a right control lever 6b are arranged. Further, an electric operation panel 18 having switch buttons, switch levers, etc. of an electric control system is provided on the side of the driver's seat 11 . A mower switch for activating the mower unit 13 is also arranged on the electric operation panel 18 . Note that the left control lever 6a and the right control lever 6b described above will be described as the control lever 6 when there is no particular need to distinguish them.

In the present embodiment, the left drive wheel 2a and the right drive wheel 2b are powered by torque from a left motor 21 and a right motor 22, which are in-wheel motors, respectively. The left motor 21 is supplied with power through a left power supply section 41 that constitutes the inverter 7 , and the right motor 22 is supplied with power through a right power supply section 42 that constitutes the inverter 7 . At least one of the rotation speed and the torque can be changed by changing the electric power supplied. The rotation speed (peripheral speed) of the left drive wheel 2a and the right drive wheel 2b can be made different from each other, and the direction of the riding electric lawn mower is changed by the rotation speed difference between the left drive wheel 2a and the right drive wheel 2b.

The travel control unit 3 is a functional unit that controls travel and turning of the riding electric lawn mower. ). The inverter 7 supplies power to each of the left motor 21 and the right motor 22 . The electric power output from the inverter 7 corresponds to the speed instruction value (target value) calculated by the travel control device 1, but the actual rotation speed (actual speed) may become smaller than the target value due to the travel load. If so, the power is modified to increase the motor output torque. On the other hand, when the actual rotation speed (actual speed) becomes higher than the target value, for example, on a downhill, the electric power is corrected so that the motor output torque becomes smaller.

The mower unit 13 has three rotating blades 131a, 131b, 131c. The rotary blades 131a, 131b and 131c are driven by mower motors 130a, 130b and 130c, respectively. Power is supplied to the mower motors 130 a , 130 b , 130 c through a mower power supply section 43 that constitutes the inverter 7 . The mower power supply unit 43 is controlled by the mower controller 5 . The mower control device 5 constitutes a control device 100 together with the traveling control device 1 described above.

An operation amount (swing angle) of the left steering lever 6a is detected by a left steering angle detection sensor 80a, and an operation amount (swing angle) of the right steering lever 6b is detected by a right steering angle detection sensor 80b. Further, the operation angle of the brake pedal 14 is detected by the brake detection sensor 80c, and the operation of the mower switch is detected by the mower sensor 80d. The rotation speed of the left drive wheel 2a is detected by a left rear wheel rotation detection sensor 70a, and the rotation speed of the right drive wheel 2b is detected by a right rear wheel rotation detection sensor 70b. Rotational speeds of the mower motors 130a, 130b and 130c are detected by rotation sensors 100a, 100b and 100c. The detection result of each sensor is transmitted to the control device 100 and used by the traveling control device 1 and the mower control device 5 as appropriate.

Although the details will be described later, the travel control device 1 calculates the amount of electric power to be supplied to the left motor 21 and the right motor 22 based on the operation amount of the control lever 6 . In addition, the traveling control device 1 corrects the electric power amount described above through known feedback control. That is, the travel control device 1 calculates the required drive torque (hereinafter simply referred to as required torque) required for the left motor 21 and the right motor 22 . The required torque is the amount of torque required when the actual rotation speed does not reach the target rotation speed with the control amount calculated based on the target rotation speed set according to the operation amount of the left control lever 6a or the right control lever 6b. It means the amount of torque required for the left motor 21 or the right motor 22 so that the speed becomes the target speed. The cruise control device 1 determines target rotational speeds of the left driving wheel 2a and the right driving wheel 2b based on the detection results of the left steering angle detection sensor 80a and the right steering angle detection sensor 80b, the left rear wheel rotation detection sensor 70a and the right rear wheel. The required torque is derived from the actual rotational speeds of the left drive wheel 2a and the right drive wheel 2b obtained by the rotation detection sensor 70b. The traveling control device 1 corrects the power amount based on the calculated required torque.

FIG. 3 is a block diagram schematically showing the configuration of the travel control device 1. As shown in FIG. As shown in FIG. 3, the travel control device 1 includes functional units of an instruction receiving unit 31, a speed instruction value calculation unit 32, an operation instruction determination unit 33, a speed instruction value correction unit 34, and a travel control unit 35. Configured. Each of these functional units is constructed of hardware or software, or both, with a CPU as a core member, in order to perform processing related to traveling and turning of the riding electric lawnmower. In addition to the travel control device 1, FIG. 3 also shows the left steering lever 6a, the right steering lever 6b, the travel control unit 3, the left drive wheel 2a, and the right drive wheel 2b.

The instruction receiving unit 31 receives respective operation instructions for the pair of left and right drive wheels 2 . The pair of left and right drive wheels 2 are a left drive wheel 2a and a right drive wheel 2b. Each operation instruction is an instruction consisting of the rotation direction and the rotation speed required for each of the left drive wheel 2a and the right drive wheel 2b. An operation instruction for the left driving wheel 2a is input by the left steering lever 6a, and an operation instruction for the right driving wheel 2b is input by the right steering lever 6b. The detection result of the left steering angle detection sensor 80a corresponds to the operation instruction for the left driving wheel 2a, and the detection result of the right steering angle detection sensor 80b corresponds to the operation instruction to the right driving wheel 2b. Accordingly, the instruction receiving unit 31 receives an operation instruction for the left drive wheel 2a via the left steering angle detection sensor 80a, and receives an operation instruction for the right drive wheel 2b via the right steering angle detection sensor 80b. The operation instruction received by the instruction reception unit 31 is transmitted to the speed instruction value calculation unit 32 and the operation instruction determination unit 33, which will be described later.

The speed instruction value calculator 32 calculates a speed instruction value to be instructed to the travel control unit 3 based on the operation instruction. The operation instruction is transmitted from the instruction receiving section 31 as described above. The traveling control unit 3 includes an inverter 7, a left motor 21, and a right motor 22, and controls traveling and turning of the riding electric lawn mower. Here, the operation instruction is an instruction consisting of the rotation direction and rotation speed required for each of the left drive wheel 2a and the right drive wheel 2b. The speed instruction value is an instruction value of the rotational speed required of the left motor 21 and the right motor 22 in order to realize the rotational direction and rotational speed that are the operation instructions for the left driving wheel 2a and the right driving wheel 2b, respectively. . Therefore, the speed command value calculator 32 controls the left motor 21 and the right motor 22 so that the left driving wheel 2a and the right driving wheel 2b can achieve the rotation direction and rotation speed requested as the operation instruction. Calculate the rotation speed of A calculation result by the speed instruction value calculation unit 32 is transmitted to the speed instruction value correction unit 34, which will be described later.

Based on the operation instruction, the operation instruction determination unit 33 determines whether the operation instruction is to rotate the pair of left and right driving wheels 2 in the same direction or to rotate the pair of left and right driving wheels 2 in different directions. do.

Here, in this embodiment, when the left steering lever 6a is tilted forward with respect to the neutral state, the left driving wheel 2a rotates the left motor 21 so that the riding electric lawn mower runs forward, and the left steering lever 6a is rotated. is tilted backward with respect to the neutral state, the left drive wheel 2a rotates the left motor 21 so that the riding electric lawn mower runs backward. On the other hand, when the right steering lever 6b is tilted forward with respect to the neutral state, the right drive wheel 2b rotates the right motor 22 so that the riding electric lawn mower runs forward, and the right steering lever 6b is moved forward with respect to the neutral state. When tilted backward, the right drive wheel 2b rotates the right motor 22 so that the riding electric lawn mower runs backward. Further, when the left control lever 6a and the right control lever 6b are in the neutral state, the left motor 21 and the right motor 22 are configured not to rotate. Also, the left control lever 6a and the right control lever 6b can be tilted in different directions with respect to the neutral state, and in this case the riding electric lawn mower can be turned (rotated) on the spot.

An operation instruction is transmitted from the instruction reception unit 31 to the operation instruction determination unit 33 . The operation instruction is an instruction consisting of the rotation direction and the rotation speed required for each of the left drive wheel 2a and the right drive wheel 2b. The operation instruction determination unit 33 determines whether the direction of rotation requested for the left driving wheel 2a and the direction of rotation requested for the right driving wheel 2b are the same or different. Determine if there is A determination result by the operation instruction determination unit 33 is transmitted to the speed command value correction unit 34, which will be described later.

The speed instruction value correction unit 34 corrects the speed instruction value for the travel control unit 3 calculated by the speed instruction value calculation unit 32 when the operation instruction is an operation instruction to rotate the pair of left and right driving wheels 2 in the same direction. Among them, one speed command value is corrected based on the other speed command value. “When the operation instruction is an operation instruction to rotate the pair of left and right driving wheels 2 in the same direction” is specified by the determination result transmitted from the operation instruction determination unit 33 . The "speed instruction value for the travel control unit 3 calculated by the speed instruction value calculation unit 32" means that the left drive wheel 2a and the right drive wheel 2b each realize the rotation direction and rotation speed requested as the operation instruction. is the rotation speed of each of the left motor 21 and the right motor 22 that is possible, and is transmitted from the speed instruction value calculator 32 . One speed command value is a speed command value required for one of the left motor 21 and the right motor 22, and the other speed command value is a speed command value required for the other of the left motor 21 and the right motor 22. This is the speed indication value to be used.

In the present embodiment, the speed instruction value correction unit 34 corrects the travel control unit 3 calculated by the speed instruction value calculation unit 32 when the operation instruction is an operation instruction to rotate the pair of left and right drive wheels 2 in the same direction. among the speed command values for , the larger speed command value is corrected based on the smaller speed command value.

Specifically, the speed instruction value correction unit 34 corrects the speed instruction value as follows. First, a turning component is extracted from the speed command value required for the left motor 21 and the speed command value required for the right motor 22 . The turning component is a value obtained by subtracting the smaller speed command value from the larger speed command value among the speed command values.

The smaller speed instruction value is used as it is as the speed instruction value. The sum of the product of the smaller speed command value and the turning component and a preset damping value is used as the speed command value for the larger speed command value. The preset damping value is a value corresponding to a gain. For example, if it is set to a value smaller than 1, only the turning component can be damped. Of course, it is also possible to set it to a value of 1 or more.

In addition, when the operation instruction is an operation instruction to rotate the pair of left and right driving wheels 2 in mutually different directions, the speed instruction value correction unit 34 corrects the speed instruction to the travel control unit 3 calculated by the speed instruction value calculation unit 32. Each of the values is corrected based on the same preset attenuation value. “When the operation instruction is an operation instruction to rotate the pair of left and right driving wheels 2 in mutually different directions” is specified by the determination result transmitted from the operation instruction determination unit 33 . "The same preset attenuation value" corresponds to the above gain.

Therefore, when the left control lever 6a and the right control lever 6b are tilted in different directions with respect to the neutral state, the speed command value correction unit 34 adjusts the left side calculated by the speed command value calculation unit 32. The speed command value required for the motor 21 is corrected to the product of the speed command value and the gain, and the speed command value required for the right motor 22 calculated by the speed command value calculation unit 32 is converted to the speed command value. It is corrected to the product of the value and the above gain. The speed instruction value corrected by the speed instruction value correction unit 34 is transmitted to the travel control unit 35, which will be described later.

The travel control unit 35 supplies power to the left power supply unit 41 and the right power supply unit 42 that configure the inverter 7 based on the speed instruction value corrected by the speed instruction value correction unit 34 . As a result, the rotation of the left motor 21 and the right motor 22 is controlled, the left drive wheel 2a and the right drive wheel 2b are rotated, and the riding electric lawn mower can travel and turn. Further, the travel control unit 35 controls the rotation of the left drive wheel 2a and the right drive wheel 2b through known feedback control. That is, the travel control unit 35 calculates the rotation speed (torque) of the left drive wheel 2a, that is, the rotation speed (torque) of the left motor 21, based on the detection result of the left steering angle detection sensor 80a, and detects the right steering angle. The rotation speed (torque) of the right drive wheel 2b, that is, the rotation speed (torque) of the right motor 22 is calculated based on the detection result of the sensor 80b, and the power consumption is calculated based on these rotation speeds (torque). For this calculation, it is preferable to use a table or function representing the relationship between the operating position and the rotational speed. The rotation of the left drive wheel 2a and the right drive wheel 2b is controlled based on the electric energy calculated in this manner and the speed command value corrected by the speed command value correction unit 34. FIG.

If the tread of the riding electric lawn mower is smaller than the wheel base, the gain for the turning instruction becomes large, and the riding electric lawn mower turns too much. Therefore, it is possible to reduce the turning sensitivity of the mechanical mechanism of the riding electric lawn mower by software. Therefore, it is possible to reduce the turning speed and improve the straightness of the riding electric lawnmower. Further, the maximum speed of the riding electric lawn mower can be prevented from being damped even though the turning component is attenuated.

[Other embodiments]
In the above embodiment, an example in which the control lever 6 is mounted on the vehicle body 15 of the riding electric lawn mower has been described. It is also possible to configure so that the turning component is extracted based on the operation of the control lever 6 provided on the remote controller.

In the above embodiment, the speed instruction value correction unit 34 corrects the travel control unit 3 calculated by the speed instruction value calculation unit 32 when the operation instruction is an operation instruction to rotate the pair of left and right drive wheels 2 in the same direction. Although it has been described that the larger speed command value is corrected based on the smaller speed command value among the speed command values for the Of the speed command values for the unit 3, it is also possible to configure so that the smaller speed command value is corrected based on the larger speed command value.

In addition, the speed instruction value correction unit 34 extracts from the smaller speed instruction value of the speed instruction value required for the left motor 21 and the speed instruction value required for the right motor 22 and the two speed instruction values. Although described as correcting the speed command value to the sum of the product of the calculated turn component and the preset damping value, this is merely an example and other methods of correction are possible. In addition, the damping value is calculated based on either the larger speed command value of the two speed command values, the smaller speed command value of the two speed command values, or the difference between the two speed command values. You can As a result, it is possible to prevent the attenuation amount from becoming too large or too small, so that the traveling vehicle can be made to travel smoothly.

In the above embodiment, the speed instruction value correction unit 34 corrects the travel control unit 3 calculated by the speed instruction value calculation unit 32 when the operation instruction is an operation instruction to rotate the pair of left and right driving wheels 2 in mutually different directions. is corrected based on the same preset damping value, the speed command value correcting section 34 corrects the speed The indicated values can be configured to be used as they are without correction based on the same preset attenuation value, or can be configured to be corrected based on mutually different attenuation values. is. In such a case, for example, among the speed command values, the speed command value with the larger absolute value may be corrected based on the speed command value with the smaller absolute value, or the speed command value with the smaller absolute value may be corrected. The indicated value may be corrected based on the larger speed indicated value. In addition, the damping value is calculated based on either the larger speed command value of the two speed command values, the smaller speed command value of the two speed command values, or the difference between the two speed command values. You can As a result, it is possible to prevent the attenuation amount from becoming too large or too small, so that the traveling vehicle can be smoothly rotated.

In the above embodiment, a riding electric lawn mower is described as an example of a traveling vehicle in which the traveling control device 1 is mounted, but the traveling vehicle may be another vehicle.

INDUSTRIAL APPLICABILITY The present invention can be used in a travel control device for a traveling vehicle having a pair of left and right travel control units capable of driving a pair of left and right drive wheels, respectively.

2: driving wheel 3: travel control unit 1: travel control device 31: instruction reception unit 32: speed instruction value calculation unit 33: operation instruction determination unit 34: speed instruction value correction unit

Claims (3)

A travel control device for a traveling vehicle having a pair of left and right travel control units capable of driving a pair of left and right drive wheels, respectively,
an instruction receiving unit that receives respective operation instructions for the pair of left and right driving wheels;
a speed instruction value calculation unit that calculates a speed instruction value to be instructed to the travel control unit based on the operation instruction;
an operation instruction determination unit that determines, based on the operation instruction, whether it is an operation instruction to rotate the pair of left and right driving wheels in the same direction or an operation instruction to rotate the pair of left and right driving wheels in different directions; ,
When the operation instruction is an operation instruction to rotate the pair of left and right driving wheels in the same direction, one of the speed instruction values for the travel control unit calculated by the speed instruction value calculation section is one of the speed instruction values. a speed command value correcting unit that corrects based on the other speed command value;
with
The speed instruction value correcting unit extracts a turning component by subtracting the smaller speed instruction value from the larger speed instruction value of the one speed instruction value and the other speed instruction value. A traveling control device that uses the speed instruction value as it is and corrects the larger speed instruction value based on the turning component . The speed instruction value correcting unit corrects the speed instruction value for the travel control unit calculated by the speed instruction value calculating unit when the operation instruction is an operation instruction to rotate the pair of left and right driving wheels in directions different from each other. is corrected based on the same preset damping value. 2. The speed instruction value correcting unit corrects the larger speed instruction value to be the sum of the smaller speed instruction value and the product of the turning component and a preset damping value. 3. or the traveling control device according to 2.

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